Implements ES6 String.prototype.normalize method.

src/i18n.js

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 27 matching lines @@
 
 var Intl = {};
 
 var undefined = global.undefined;
 
 var AVAILABLE_SERVICES = ['collator',
                           'numberformat',
                           'dateformat',
                           'breakiterator'];
 
+var NORMALIZATION_FORMS = ['NFC',
+                           'NFD',
+                           'NFKC',
+                           'NFKD'];
+
 /**
  * Caches available locales for each service.
  */
 var AVAILABLE_LOCALES = {
   'collator': undefined,
   'numberformat': undefined,
   'dateformat': undefined,
   'breakiterator': undefined
 };
 
@@ skipping 1922 matching lines @@
   writable: true,
   configurable: true,
   enumerable: false
 });
 %FunctionSetName($String.prototype.localeCompare, 'localeCompare');
 %FunctionRemovePrototype($String.prototype.localeCompare);
 %SetNativeFlag($String.prototype.localeCompare);
 
 
 /**
+ * Unicode normalization. This method is called with one argument that
+ * specifies the normalization form.
+ * If none is specified, "NFC" is assumed.
+ * If the form is not one of "NFC", "NFD", "NFKC", or "NFKD", then throw
+ * a RangeError Exception.
+ */
+$Object.defineProperty($String.prototype, 'normalize', {
+  value: function(that) {
+    if (%_IsConstructCall()) {
+      throw new $TypeError(ORDINARY_FUNCTION_CALLED_AS_CONSTRUCTOR);
+    }
+
+    if (IS_NULL_OR_UNDEFINED(this)) {

[mathias, 2014/01/29 09:03:38]

You should use `CHECK_OBJECT_COERCIBLE` here as per step 1 in the spec.
https://people.mozilla.org/~jorendorff/es6-draft.html#sec-string.prototype.no...

+      throw new $TypeError('Method invoked on undefined or null value.');
+    }
+
+    var form = $String(%_Arguments(0) || 'NFC');
+
+    var normalizationForm = NORMALIZATION_FORMS.indexOf(form);
+    if (normalizationForm === -1) {
+      throw new $RangeError('The normalization form should be one of '
+          + NORMALIZATION_FORMS.join(', ') + '.');
+    }
+
+    return %StringNormalize(this, normalizationForm);
+  },
+  writable: true,
+  configurable: true,
+  enumerable: false
+});
+%FunctionSetName($String.prototype.normalize, 'normalize');
+%FunctionRemovePrototype($String.prototype.normalize);
+%SetNativeFlag($String.prototype.normalize);
+
+
+/**
  * Formats a Number object (this) using locale and options values.
  * If locale or options are omitted, defaults are used.
  */
 $Object.defineProperty($Number.prototype, 'toLocaleString', {
   value: function() {
     if (%_IsConstructCall()) {
       throw new $TypeError(ORDINARY_FUNCTION_CALLED_AS_CONSTRUCTOR);
     }
 
     if (!(this instanceof $Number) && typeof(this) !== 'number') {
@@ skipping 104 matching lines @@
   writable: true,
   configurable: true,
   enumerable: false
 });
 %FunctionSetName($Date.prototype.toLocaleTimeString, 'toLocaleTimeString');
 %FunctionRemovePrototype($Date.prototype.toLocaleTimeString);
 %SetNativeFlag($Date.prototype.toLocaleTimeString);
 
 return Intl;
 }())});